1. Field of the Invention
This invention relates to a tracer control system which permits arbitrary setting up of the directions of feed.
2. Description of the Prior Art
For surface profiling (180.degree. profiling), the direction of feed is usually defined in the X- or Y-axis direction, but according to the configuration of a model, the accuracy of profiling may sometimes be enhanced by a feed at an arbitrary angle rather than in the X- or Y-axis directions. For example, in the case of the model being square-shaped, it is difficult to profile its four-cornered portions in the X- or Y-axis directions; to avoid this difficulty, there has been proposed a tracer control system which performs the feed at an arbitrary angle to the X- or Y-axis.
An example of the conventional system is such as disclosed in Japanese Patent Disclosure No. 33579/75 in which two coordinate conversion circuits, each formed by a resolver, are mechanically interlocked with each other, thereby to set up the direction of feed.
In such a system, however, since the two coordinate conversion circuits are mechanically ganged with each other for setting up the direction of feed, a high degree of mechanical accuracy, (and consequently a complicated arrangement) is needed for accurate profiling.